State Department officials are set to release a new batch of Hillary Clinton's private emails Friday amid fresh legal woes for the Democratic front-runner and her closest confidantes.

The release will likely come just hours before voters head to the polls in South Carolina, where Clinton is expected to notch an easy victory Saturday over her rival, Sen. Bernie Sanders.

It will be the third batch of emails published this month, and the last before a final release of thousands of pages slated for Feb. 29.

At least 22 emails have been withheld by the State Department this year because they contained top secret information, raising uncomfortable questions for the former secretary of state on the campaign trail.

But Clinton suffered a larger setback this week in an unrelated Freedom of Information Act lawsuit that could further complicate her attempts to shake the email controversy.

In a FOIA case focused on one of Clinton's top aides, Huma Abedin, a judge this week ruled staffers with knowledge of Clinton's personal server network should have to answer questions under oath about the email arrangement.

The federal judge even threatened to subpoena Clinton herself to learn more about why the Democratic front-runner decided to use the server in the first place, and how her team decided which emails to erase from that server.

More than 1,700 of Clinton's private emails have been classified since the State Department began releasing them at the end of every month since June of last year.